Stereoselective synthesis of unnatural aminoacids cis-4-hydroxyproline and bulgecinine

Article abstract of DOI:10.1016/0957-4166(96)00079-1

A new stereoselective synthesis of both (2R,4R)- and (2S,4S)-4-hydroxy-proline and (+)- and (-)-bulgecinine was performed starting from synthons 1 or 1', respectively. The synthetic route has been established via a novel assisted cleavage of a disubstituted amide in mild conditions and successive stereocontrolled iodocyclization.